thirteenth paper

Question 1

what is Hubbles law?

Answer 1

the more distant the galaxy, the higher its recession velocity

Question 2

is the universe static?

Answer 2

no

Question 3

how old is the universe?

Answer 3

13.8 billion years old

Question 4

what happens as the universe expands?

Answer 4

light waves are stretched out and the energy is reduced

Question 5

what is redshift?

Answer 5

the time to receive light is lengthened over the time it takes to emit a photon

Question 6

galaxies are not moving away from space, they are moving away…

Answer 6

with space.
as if space is still expanding

Question 7

the universe used to be much more…

Answer 7

compressed

Question 8

are the galaxies moving towards or away from each other?

Answer 8

away

Question 9

what is the big bang theory?

Answer 9

the universe was a very small, hot, and dense entity that rapidly expanded.

Question 10

when did the big bang happen?

Answer 10

14 billion years ago

Question 11

how far away is the andromeda galaxy? and how many years in the past do we see it?

Answer 11

2.3 million light years away.
we see it 2.3 million years ago

Question 12

what makes it possible to see the big bang directly?

Answer 12

the look back time

Question 13

what is the look back time to nearby galaxies?

Answer 13

a few million years

Question 14

the big bang did not occur in a single place but filled the entire volume of the ____

Answer 14

universe

Question 15

4 step progression of the big bang

Answer 15

1) initially the universe was full of photons
2) within the first 4 seconds, protons, neutrons, and electrons formed
3) deuterium and He nuclei formed in the first 3 minutes
4) after 1/2 a million years gravity began to forming galaxies and stars

Question 16

3 points of experimental energy that support the big bang

Answer 16

1) cosmological redshift
2) cosmic microwave backround
3) H to He mass ratio of 1-3

Question 17

what is cosmological redshift?

Answer 17

galaxies today have a redshift in their spectrum line

Question 18

what is cosmic microwave backround?

Answer 18

microwave radiation that fills all space and is thought to represent the redshifted glow from Big Bang

Question 19

What is H to He ratio of 3-1?

Answer 19

in stars and interstellar material we see this ratio

Question 20

the evolution of the universe in 5 steps

Answer 20

1)elementary particles
2)protons, neutrons, and electrons
3)plasma of hydrogen and helium nuclei
4) atoms
5) stars and galaxies

Question 21

what is the particle era?

Answer 21

ordinary particles start to form.

Question 22

why did the universe create slightly more matter particles then antimatter particles?

Answer 22

if the numbers where the same, the particles would eventually annihilate entirely and their would be only photons in the universe

Question 23

what is the era of nucleosynthesis?

Answer 23

fusion that happened about 3 minutes after the big bang

Question 24

what 2 things happened during the era of nucleosynthesis?

Answer 24

1) the first stars were made
2) all heavier elements were created

Question 25

what happened in the era of nuclei?

Answer 25

H and He nuclei began to capture free electrons and gas became transparent

Question 26

define nucleosynthesis

Answer 26

fusion of heavier elements up to iron

Question 27

4 possible scenarios for expansion/contraction of the universe

Answer 27

1) closed, high density universe that expands for several billion years, then turns around and collapses on itself 2) flat, critical density universe in which the expansion rated continually slow down 3) open, low density universe whose expansion is also slowing down but less than closed and flat 4) large fraction of the matter is in a form dubbed "dark energy" which is causing the universes expansion to accelerate

Question 28

universe is 0/0 matter and 0/0 dark matter

Answer 28

1/3 2/3

Question 29

composition of the cosmos % dark energy % dark matter % hydrogen and helium % stars % ghostly neutrinos % heavy elements

Answer 29

65 30 4 0.5 0.3 0.3